Have you ever asked Why is the weather often wrong? It's already using advanced technology? Weather applications show it's sunny today, but it's actually raining heavily. Or vice versa, predicted rain but not a drop of water came down. Understand Why is the weather often wrong? It helps us use more intelligent and realistic weather information.
The atmosphere is the Caotic System
The fundamental reason weather forecasts aren't always right is the nature of the atmosphere itself. Earth's atmosphere is a very complex and caotic system in the scientific sense. That is, a small change in the initial condition can result in a huge difference in the end result — This phenomenon is known as the butterfly effect.
Imagine a marbles you put on the top of a hill. A different initial position only 1 millimeter will determine whether the marbles fall left or right. Likewise the atmosphere — The temperature difference is 0.1 ° C at a point in the Pacific Ocean could produce a significant difference in the Jakarta weather a week later.
Data Collection Limit
Weather forecasts can only be as accurate as the data entered into the model. Unfortunately, the measurements of the atmosphere are still far from perfect. Although there are thousands of weather stations, radiosonde balloons, and satellites, there are still vast areas — Especially in tropical oceans and forests — Who lack observation.
In Indonesia, these limitations are very real. Many remote islands have no weather stations. As a result, the weather model has to extract or interpolate data from the nearest station. Therefore, forecasts for remote areas tend to be less accurate than the forecasts for large cities that have many observation stations.
Numeric Weather Model limitations
Numeric weather models are computer programs that simulate atmospheric behavior. Although highly sophisticated, this model has fundamental limitations that cannot be fully handled with current technology.
First, weather models divide the atmosphere into grid boxes of 925 km. All conditions in one box are considered uniforms. However, a weather phenomenon like a local lightning storm could occur in a much smaller area than one grid. As a result, models cannot predict local rain properly.
Secondly, some atmospheric physics processes are very hard to model mathematically. Formation of clouds, interactions of rain with wind, and the effect of mountains against the air flow is an example of a process that is still predicted by aproxization. Therefore, there's always a level of uncertainty in any weather forecast.
Accurate By Time Term
The weather predictive accuracy is significantly decreasing as the prediction increases. Here's a general picture of an accuracy rate based on the time frame.
| Time Term | Accurate Level | Utility |
|---|---|---|
| 1 -3 hours ahead | 90–95% | Short-term outdoor activity |
| One more day. | 80–90% | Daily planning |
| Three days from now. | 70–80% | Weekend planning |
| The next 5 days | 55–65% | General image only |
| The next 7 days | 40–55% | Indications of weather trends |
| 10 + days ahead | Under 40% | Very unreliable |
Predictable Local Factor
Indonesia has a very complex topography — Thousands of islands, high mountains, deep valleys, and long shoreline. All of these factors create microweather conditions that are very hard to predict by global models.
For example, the weather on the west and east side of Mount Salak can be very different even if it's only a few kilometers away. The wind that carries water vapor from the western ocean rises to the mountains and rains on the west side, while the east side remains dry because of the rain. These phenomena are hard to catch by low-resolution weather models.
How to Use Weather Predictions Polite
Understanding the limits of weather forecast helps us use it more realistically. Here's some practical tips.
First, always use short-term forecasts (1-3 days) for important decisions. Seven-day foreplay is just a general image, not certainty. Second, look at the percentage of the rainfall. — 30% means there's still a 70% chance of not raining. Third, combine multiple predictive sources like Cuaca.in, BMKG, and AccuWeather to get a more complete picture.
Fourth, notice the signs of natural weather around you, the rising cumulonimbus cloud is almost always followed by heavy rain in 1-2 hours. The morning red skies often indicate the worst weather is coming. Fifth, use it Extreme weather warning tool In the early anticipation of a dangerous condition.
